Here are the rules. So S3 variables start with LAKEFS_BLOCKSTORE_S3_..., and your example doesn't include that "S3".

@Ariel Shaqed (Scolnicov) S3 was the issue, thanks 🎉

Nice! We managed to close down many of the configuration loopholes by really validating the YAML file, but environment variables are hard to control. And secrets go in there and there are so many ways to configure the block stores, so I'm not sure how we could nail that area down.